Ecosystem services; regulating and supporting services with examples

Meaning of ecosystem services

Ecosystem services are the benefits that people receive from the normal working of ecosystems: the products of ecosystem processes, such as the cleaning of air and water by forests. Many of them are indirect: we do not buy them, yet we cannot live without them. The DU syllabus groups them into four kinds:

• Provisioning services: goods we take directly, such as food, water, timber and medicinal plants.
• Regulating services: the control of natural processes, such as climate, floods and pests.
• Cultural services: non-material benefits, such as recreation, beauty, learning and spiritual value.
• Supporting services: the basic processes on which all the others depend, such as soil formation and nutrient cycling.

Regulating services

These services keep the environment stable and safe by controlling natural processes.

1. Climate moderation. Climate moderation is one of the indirect benefits that living systems give us: vegetation takes in carbon dioxide and gives off water vapour, which tempers local and global climate. A city with large green belts, such as the Delhi Ridge forest, is cooler in summer than its paved neighbourhoods.
2. Flood control and water regulation. A forest soaks up monsoon rain and releases it slowly through streams for the rest of the year; wetlands and flood plains hold surplus water. When catchments are deforested, flash floods and dry streams follow.
3. Pollination. Bees, butterflies, birds and bats carry pollen from flower to flower; without them crops such as mustard, mango and many vegetables would yield little.
4. Pest control. Birds, frogs, spiders and predatory insects keep crop pests in check, reducing the need for chemical pesticides.
5. Purification of air and water. Forests clean the air, and wetlands and soils filter water.
6. Control of soil erosion. Roots and ground cover hold the soil in place on slopes and riverbanks.

Supporting services

These are the underlying processes that make every other service possible; their benefits reach us only indirectly and over long periods.

1. Primary production. Green plants capture sunlight in photosynthesis and build organic matter; this production is the food base for every herbivore and decomposer in the ecosystem.
2. Nutrient cycling. Nutrients such as carbon, nitrogen and phosphorus move from soil and air into living things and back again, so they can be used over and over.
3. Decomposition. Decomposers break dead leaves, wood and animal remains into carbon dioxide, water and nutrients; earthworms, the farmer's friend, also loosen the soil.
4. Soil formation. Over long periods, weathered rock mixed with this decomposed organic matter forms fertile soil, on which farming depends.
5. Habitat provision. Ecosystems give species places to live and breed; mangroves along India's east coast, for example, shelter the young of many fish and prawns.

Conclusion

Regulating services protect us from extremes, and supporting services keep the whole system running. Because neither is sold in a market, both are easily lost when forests, wetlands and soils are degraded, and their loss shows up later as floods, crop failure or pollution.